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fat: Fix and cleanup timestamp conversion
[deliverable/linux.git] / fs / fat / inode.c
CommitLineData
1da177e4
LT		 1/*
2 * linux/fs/fat/inode.c
3 *
4 * Written 1992,1993 by Werner Almesberger
5 * VFAT extensions by Gordon Chaffee, merged with msdos fs by Henrik Storner
6 * Rewritten for the constant inumbers support by Al Viro
7 *
8 * Fixes:
9 *
10 * Max Cohan: Fixed invalid FSINFO offset when info_sector is 0
11 */
12
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/time.h>
16#include <linux/slab.h>
17#include <linux/smp_lock.h>
18#include <linux/seq_file.h>
1da177e4 19#include <linux/pagemap.h>
a5425d29 20#include <linux/mpage.h>
1da177e4 21#include <linux/buffer_head.h>
a5694255 22#include <linux/exportfs.h>
1da177e4
LT		 23#include <linux/mount.h>
24#include <linux/vfs.h>
25#include <linux/parser.h>
e5174baa 26#include <linux/uio.h>
ae78bf9c 27#include <linux/writeback.h>
e7d709c0 28#include <linux/log2.h>
1da177e4 29#include <asm/unaligned.h>
9e975dae 30#include "fat.h"
1da177e4
LT		 31
32#ifndef CONFIG_FAT_DEFAULT_IOCHARSET
33/* if user don't select VFAT, this is undefined. */
34#define CONFIG_FAT_DEFAULT_IOCHARSET ""
35#endif
36
37static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
38static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
39
40
41static int fat_add_cluster(struct inode *inode)
42{
43 int err, cluster;
44
45 err = fat_alloc_clusters(inode, &cluster, 1);
46 if (err)
47 return err;
48 /* FIXME: this cluster should be added after data of this
49 * cluster is writed */
50 err = fat_chain_add(inode, cluster, 1);
51 if (err)
52 fat_free_clusters(inode, cluster);
53 return err;
54}
55
6a1d9805
OH		 56static inline int __fat_get_block(struct inode *inode, sector_t iblock,
57 unsigned long *max_blocks,
58 struct buffer_head *bh_result, int create)
1da177e4
LT		 59{
60 struct super_block *sb = inode->i_sb;
e5174baa 61 struct msdos_sb_info *sbi = MSDOS_SB(sb);
e5174baa 62 unsigned long mapped_blocks;
6a1d9805 63 sector_t phys;
e5174baa 64 int err, offset;
1da177e4 65
e5174baa 66 err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
1da177e4
LT		 67 if (err)
68 return err;
69 if (phys) {
70 map_bh(bh_result, sb, phys);
e5174baa 71 *max_blocks = min(mapped_blocks, *max_blocks);
1da177e4
LT		 72 return 0;
73 }
74 if (!create)
75 return 0;
e5174baa 76
1da177e4
LT		 77 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
78 fat_fs_panic(sb, "corrupted file size (i_pos %lld, %lld)",
6a1d9805 79 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
1da177e4
LT		 80 return -EIO;
81 }
e5174baa
OH		 82
83 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
84 if (!offset) {
85 /* TODO: multiple cluster allocation would be desirable. */
1da177e4
LT		 86 err = fat_add_cluster(inode);
87 if (err)
88 return err;
89 }
e5174baa
OH		 90 /* available blocks on this cluster */
91 mapped_blocks = sbi->sec_per_clus - offset;
92
93 *max_blocks = min(mapped_blocks, *max_blocks);
94 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
95
96 err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
1da177e4
LT		 97 if (err)
98 return err;
6a1d9805 99
e5174baa
OH		 100 BUG_ON(!phys);
101 BUG_ON(*max_blocks != mapped_blocks);
1da177e4
LT		 102 set_buffer_new(bh_result);
103 map_bh(bh_result, sb, phys);
6a1d9805 104
1da177e4
LT		 105 return 0;
106}
107
6a1d9805
OH		 108static int fat_get_block(struct inode *inode, sector_t iblock,
109 struct buffer_head *bh_result, int create)
e5174baa
OH		 110{
111 struct super_block *sb = inode->i_sb;
1d8fa7a2 112 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
6a1d9805 113 int err;
e5174baa 114
6a1d9805 115 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
e5174baa
OH		 116 if (err)
117 return err;
118 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
119 return 0;
120}
121
1da177e4
LT		 122static int fat_writepage(struct page *page, struct writeback_control *wbc)
123{
124 return block_write_full_page(page, fat_get_block, wbc);
125}
126
a5425d29
OH		 127static int fat_writepages(struct address_space *mapping,
128 struct writeback_control *wbc)
129{
130 return mpage_writepages(mapping, wbc, fat_get_block);
131}
132
1da177e4
LT		 133static int fat_readpage(struct file *file, struct page *page)
134{
a5425d29
OH		 135 return mpage_readpage(page, fat_get_block);
136}
137
138static int fat_readpages(struct file *file, struct address_space *mapping,
139 struct list_head *pages, unsigned nr_pages)
140{
141 return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
1da177e4
LT		 142}
143
d7777a25
NP		 144static int fat_write_begin(struct file *file, struct address_space *mapping,
145 loff_t pos, unsigned len, unsigned flags,
146 struct page **pagep, void **fsdata)
1da177e4 147{
d7777a25
NP		 148 *pagep = NULL;
149 return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
150 fat_get_block,
151 &MSDOS_I(mapping->host)->mmu_private);
1da177e4
LT		 152}
153
d7777a25
NP		 154static int fat_write_end(struct file *file, struct address_space *mapping,
155 loff_t pos, unsigned len, unsigned copied,
156 struct page *pagep, void *fsdata)
ef402268 157{
d7777a25
NP		 158 struct inode *inode = mapping->host;
159 int err;
160 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
161 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
ef402268
OH		 162 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
163 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
164 mark_inode_dirty(inode);
165 }
166 return err;
167}
168
e5174baa
OH		 169static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
170 const struct iovec *iov,
171 loff_t offset, unsigned long nr_segs)
172{
173 struct file *file = iocb->ki_filp;
174 struct inode *inode = file->f_mapping->host;
175
176 if (rw == WRITE) {
177 /*
4e02ed4b 178 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
e5174baa
OH		 179 * so we need to update the ->mmu_private to block boundary.
180 *
181 * But we must fill the remaining area or hole by nul for
182 * updating ->mmu_private.
94412a96
OH		 183 *
184 * Return 0, and fallback to normal buffered write.
e5174baa
OH		 185 */
186 loff_t size = offset + iov_length(iov, nr_segs);
187 if (MSDOS_I(inode)->mmu_private < size)
94412a96 188 return 0;
e5174baa
OH		 189 }
190
191 /*
192 * FAT need to use the DIO_LOCKING for avoiding the race
193 * condition of fat_get_block() and ->truncate().
194 */
195 return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
6a1d9805 196 offset, nr_segs, fat_get_block, NULL);
e5174baa
OH		 197}
198
1da177e4
LT		 199static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
200{
201 return generic_block_bmap(mapping, block, fat_get_block);
202}
203
f5e54d6e 204static const struct address_space_operations fat_aops = {
1da177e4 205 .readpage = fat_readpage,
a5425d29 206 .readpages = fat_readpages,
1da177e4 207 .writepage = fat_writepage,
a5425d29 208 .writepages = fat_writepages,
1da177e4 209 .sync_page = block_sync_page,
d7777a25
NP		 210 .write_begin = fat_write_begin,
211 .write_end = fat_write_end,
e5174baa 212 .direct_IO = fat_direct_IO,
1da177e4
LT		 213 .bmap = _fat_bmap
214};
215
216/*
217 * New FAT inode stuff. We do the following:
218 * a) i_ino is constant and has nothing with on-disk location.
219 * b) FAT manages its own cache of directory entries.
220 * c) *This* cache is indexed by on-disk location.
221 * d) inode has an associated directory entry, all right, but
222 * it may be unhashed.
223 * e) currently entries are stored within struct inode. That should
224 * change.
225 * f) we deal with races in the following way:
226 * 1. readdir() and lookup() do FAT-dir-cache lookup.
227 * 2. rename() unhashes the F-d-c entry and rehashes it in
228 * a new place.
229 * 3. unlink() and rmdir() unhash F-d-c entry.
230 * 4. fat_write_inode() checks whether the thing is unhashed.
231 * If it is we silently return. If it isn't we do bread(),
232 * check if the location is still valid and retry if it
233 * isn't. Otherwise we do changes.
234 * 5. Spinlock is used to protect hash/unhash/location check/lookup
235 * 6. fat_clear_inode() unhashes the F-d-c entry.
236 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
237 * and consider negative result as cache miss.
238 */
239
240static void fat_hash_init(struct super_block *sb)
241{
242 struct msdos_sb_info *sbi = MSDOS_SB(sb);
243 int i;
244
245 spin_lock_init(&sbi->inode_hash_lock);
246 for (i = 0; i < FAT_HASH_SIZE; i++)
247 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
248}
249
250static inline unsigned long fat_hash(struct super_block *sb, loff_t i_pos)
251{
252 unsigned long tmp = (unsigned long)i_pos | (unsigned long) sb;
253 tmp = tmp + (tmp >> FAT_HASH_BITS) + (tmp >> FAT_HASH_BITS * 2);
254 return tmp & FAT_HASH_MASK;
255}
256
257void fat_attach(struct inode *inode, loff_t i_pos)
258{
259 struct super_block *sb = inode->i_sb;
260 struct msdos_sb_info *sbi = MSDOS_SB(sb);
261
262 spin_lock(&sbi->inode_hash_lock);
263 MSDOS_I(inode)->i_pos = i_pos;
264 hlist_add_head(&MSDOS_I(inode)->i_fat_hash,
265 sbi->inode_hashtable + fat_hash(sb, i_pos));
266 spin_unlock(&sbi->inode_hash_lock);
267}
268
7c709d00 269EXPORT_SYMBOL_GPL(fat_attach);
1da177e4
LT		 270
271void fat_detach(struct inode *inode)
272{
273 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
274 spin_lock(&sbi->inode_hash_lock);
275 MSDOS_I(inode)->i_pos = 0;
276 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
277 spin_unlock(&sbi->inode_hash_lock);
278}
279
7c709d00 280EXPORT_SYMBOL_GPL(fat_detach);
1da177e4
LT		 281
282struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
283{
284 struct msdos_sb_info *sbi = MSDOS_SB(sb);
285 struct hlist_head *head = sbi->inode_hashtable + fat_hash(sb, i_pos);
286 struct hlist_node *_p;
287 struct msdos_inode_info *i;
288 struct inode *inode = NULL;
289
290 spin_lock(&sbi->inode_hash_lock);
291 hlist_for_each_entry(i, _p, head, i_fat_hash) {
292 BUG_ON(i->vfs_inode.i_sb != sb);
293 if (i->i_pos != i_pos)
294 continue;
295 inode = igrab(&i->vfs_inode);
296 if (inode)
297 break;
298 }
299 spin_unlock(&sbi->inode_hash_lock);
300 return inode;
301}
302
303static int is_exec(unsigned char *extension)
304{
305 unsigned char *exe_extensions = "EXECOMBAT", *walk;
306
307 for (walk = exe_extensions; *walk; walk += 3)
308 if (!strncmp(extension, walk, 3))
309 return 1;
310 return 0;
311}
312
313static int fat_calc_dir_size(struct inode *inode)
314{
315 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
316 int ret, fclus, dclus;
317
318 inode->i_size = 0;
319 if (MSDOS_I(inode)->i_start == 0)
320 return 0;
321
322 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
323 if (ret < 0)
324 return ret;
325 inode->i_size = (fclus + 1) << sbi->cluster_bits;
326
327 return 0;
328}
329
330/* doesn't deal with root inode */
331static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
332{
333 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
334 int error;
335
336 MSDOS_I(inode)->i_pos = 0;
337 inode->i_uid = sbi->options.fs_uid;
338 inode->i_gid = sbi->options.fs_gid;
339 inode->i_version++;
340 inode->i_generation = get_seconds();
341
342 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
343 inode->i_generation &= ~1;
344 inode->i_mode = MSDOS_MKMODE(de->attr,
345 S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
346 inode->i_op = sbi->dir_ops;
347 inode->i_fop = &fat_dir_operations;
348
349 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
350 if (sbi->fat_bits == 32)
351 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
352
353 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
354 error = fat_calc_dir_size(inode);
355 if (error < 0)
356 return error;
357 MSDOS_I(inode)->mmu_private = inode->i_size;
358
359 inode->i_nlink = fat_subdirs(inode);
360 } else { /* not a directory */
361 inode->i_generation |= 1;
362 inode->i_mode = MSDOS_MKMODE(de->attr,
9aacd599 363 ((sbi->options.showexec && !is_exec(de->name + 8))
1da177e4
LT		 364 ? S_IRUGO|S_IWUGO : S_IRWXUGO)
365 & ~sbi->options.fs_fmask) | S_IFREG;
366 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
367 if (sbi->fat_bits == 32)
368 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
369
370 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
371 inode->i_size = le32_to_cpu(de->size);
372 inode->i_op = &fat_file_inode_operations;
373 inode->i_fop = &fat_file_operations;
374 inode->i_mapping->a_ops = &fat_aops;
375 MSDOS_I(inode)->mmu_private = inode->i_size;
376 }
377 if (de->attr & ATTR_SYS) {
378 if (sbi->options.sys_immutable)
379 inode->i_flags |= S_IMMUTABLE;
380 }
381 MSDOS_I(inode)->i_attrs = de->attr & ATTR_UNUSED;
1da177e4
LT		 382 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
383 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
7decd1cb
OH		 384
385 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
1da177e4 386 if (sbi->options.isvfat) {
7decd1cb
OH		 387 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
388 de->cdate, de->ctime_cs);
389 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
1da177e4 390 } else
62a36c43 391 inode->i_ctime = inode->i_atime = inode->i_mtime;
1da177e4
LT		 392
393 return 0;
394}
395
396struct inode *fat_build_inode(struct super_block *sb,
397 struct msdos_dir_entry *de, loff_t i_pos)
398{
399 struct inode *inode;
400 int err;
401
402 inode = fat_iget(sb, i_pos);
403 if (inode)
404 goto out;
405 inode = new_inode(sb);
406 if (!inode) {
407 inode = ERR_PTR(-ENOMEM);
408 goto out;
409 }
410 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
411 inode->i_version = 1;
412 err = fat_fill_inode(inode, de);
413 if (err) {
414 iput(inode);
415 inode = ERR_PTR(err);
416 goto out;
417 }
418 fat_attach(inode, i_pos);
419 insert_inode_hash(inode);
420out:
421 return inode;
422}
423
7c709d00 424EXPORT_SYMBOL_GPL(fat_build_inode);
1da177e4
LT		 425
426static void fat_delete_inode(struct inode *inode)
427{
fef26658 428 truncate_inode_pages(&inode->i_data, 0);
3754a544
OH		 429 inode->i_size = 0;
430 fat_truncate(inode);
1da177e4
LT		 431 clear_inode(inode);
432}
433
434static void fat_clear_inode(struct inode *inode)
435{
8f593427
LT		 436 struct super_block *sb = inode->i_sb;
437 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1da177e4 438
1da177e4
LT		 439 spin_lock(&sbi->inode_hash_lock);
440 fat_cache_inval_inode(inode);
441 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
442 spin_unlock(&sbi->inode_hash_lock);
1da177e4
LT		 443}
444
a6bf6b21 445static void fat_write_super(struct super_block *sb)
1da177e4 446{
a6bf6b21 447 sb->s_dirt = 0;
1da177e4
LT		 448
449 if (!(sb->s_flags & MS_RDONLY))
450 fat_clusters_flush(sb);
a6bf6b21
OH		 451}
452
453static void fat_put_super(struct super_block *sb)
454{
455 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1da177e4
LT		 456
457 if (sbi->nls_disk) {
458 unload_nls(sbi->nls_disk);
459 sbi->nls_disk = NULL;
460 sbi->options.codepage = fat_default_codepage;
461 }
462 if (sbi->nls_io) {
463 unload_nls(sbi->nls_io);
464 sbi->nls_io = NULL;
465 }
466 if (sbi->options.iocharset != fat_default_iocharset) {
467 kfree(sbi->options.iocharset);
468 sbi->options.iocharset = fat_default_iocharset;
469 }
470
471 sb->s_fs_info = NULL;
472 kfree(sbi);
473}
474
e18b890b 475static struct kmem_cache *fat_inode_cachep;
1da177e4
LT		 476
477static struct inode *fat_alloc_inode(struct super_block *sb)
478{
479 struct msdos_inode_info *ei;
8f593427 480 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
1da177e4
LT		 481 if (!ei)
482 return NULL;
483 return &ei->vfs_inode;
484}
485
486static void fat_destroy_inode(struct inode *inode)
487{
488 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
489}
490
51cc5068 491static void init_once(void *foo)
1da177e4
LT		 492{
493 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
494
a35afb83
CL		 495 spin_lock_init(&ei->cache_lru_lock);
496 ei->nr_caches = 0;
497 ei->cache_valid_id = FAT_CACHE_VALID + 1;
498 INIT_LIST_HEAD(&ei->cache_lru);
499 INIT_HLIST_NODE(&ei->i_fat_hash);
500 inode_init_once(&ei->vfs_inode);
1da177e4
LT		 501}
502
503static int __init fat_init_inodecache(void)
504{
505 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
506 sizeof(struct msdos_inode_info),
fffb60f9
PJ		 507 0, (SLAB_RECLAIM_ACCOUNT|
508 SLAB_MEM_SPREAD),
20c2df83 509 init_once);
1da177e4
LT		 510 if (fat_inode_cachep == NULL)
511 return -ENOMEM;
512 return 0;
513}
514
515static void __exit fat_destroy_inodecache(void)
516{
1a1d92c1 517 kmem_cache_destroy(fat_inode_cachep);
1da177e4
LT		 518}
519
520static int fat_remount(struct super_block *sb, int *flags, char *data)
521{
522 struct msdos_sb_info *sbi = MSDOS_SB(sb);
523 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
524 return 0;
525}
526
726c3342 527static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
1da177e4 528{
726c3342 529 struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
1da177e4
LT		 530
531 /* If the count of free cluster is still unknown, counts it here. */
606e423e 532 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
726c3342 533 int err = fat_count_free_clusters(dentry->d_sb);
1da177e4
LT		 534 if (err)
535 return err;
536 }
537
726c3342 538 buf->f_type = dentry->d_sb->s_magic;
1da177e4
LT		 539 buf->f_bsize = sbi->cluster_size;
540 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
541 buf->f_bfree = sbi->free_clusters;
542 buf->f_bavail = sbi->free_clusters;
543 buf->f_namelen = sbi->options.isvfat ? 260 : 12;
544
545 return 0;
546}
547
548static int fat_write_inode(struct inode *inode, int wait)
549{
550 struct super_block *sb = inode->i_sb;
551 struct msdos_sb_info *sbi = MSDOS_SB(sb);
552 struct buffer_head *bh;
553 struct msdos_dir_entry *raw_entry;
554 loff_t i_pos;
5f22ca9b 555 int err;
1da177e4
LT		 556
557retry:
558 i_pos = MSDOS_I(inode)->i_pos;
559 if (inode->i_ino == MSDOS_ROOT_INO || !i_pos)
560 return 0;
561
1da177e4
LT		 562 bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
563 if (!bh) {
564 printk(KERN_ERR "FAT: unable to read inode block "
565 "for updating (i_pos %lld)\n", i_pos);
5f22ca9b 566 return -EIO;
1da177e4
LT		 567 }
568 spin_lock(&sbi->inode_hash_lock);
569 if (i_pos != MSDOS_I(inode)->i_pos) {
570 spin_unlock(&sbi->inode_hash_lock);
571 brelse(bh);
1da177e4
LT		 572 goto retry;
573 }
574
575 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
576 [i_pos & (sbi->dir_per_block - 1)];
577 if (S_ISDIR(inode->i_mode))
578 raw_entry->size = 0;
579 else
580 raw_entry->size = cpu_to_le32(inode->i_size);
581 raw_entry->attr = fat_attr(inode);
582 raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
583 raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
7decd1cb
OH		 584 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
585 &raw_entry->date, NULL);
1da177e4 586 if (sbi->options.isvfat) {
62a36c43 587 __le16 atime;
7decd1cb
OH		 588 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
589 &raw_entry->cdate, &raw_entry->ctime_cs);
590 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
591 &raw_entry->adate, NULL);
1da177e4
LT		 592 }
593 spin_unlock(&sbi->inode_hash_lock);
594 mark_buffer_dirty(bh);
5f22ca9b 595 err = 0;
1da177e4
LT		 596 if (wait)
597 err = sync_dirty_buffer(bh);
598 brelse(bh);
1da177e4
LT		 599 return err;
600}
601
602int fat_sync_inode(struct inode *inode)
603{
604 return fat_write_inode(inode, 1);
605}
606
7c709d00 607EXPORT_SYMBOL_GPL(fat_sync_inode);
1da177e4
LT		 608
609static int fat_show_options(struct seq_file *m, struct vfsmount *mnt);
ee9b6d61 610static const struct super_operations fat_sops = {
1da177e4
LT		 611 .alloc_inode = fat_alloc_inode,
612 .destroy_inode = fat_destroy_inode,
613 .write_inode = fat_write_inode,
614 .delete_inode = fat_delete_inode,
615 .put_super = fat_put_super,
a6bf6b21 616 .write_super = fat_write_super,
1da177e4
LT		 617 .statfs = fat_statfs,
618 .clear_inode = fat_clear_inode,
619 .remount_fs = fat_remount,
620
1da177e4
LT		 621 .show_options = fat_show_options,
622};
623
624/*
625 * a FAT file handle with fhtype 3 is
626 * 0/ i_ino - for fast, reliable lookup if still in the cache
627 * 1/ i_generation - to see if i_ino is still valid
628 * bit 0 == 0 iff directory
629 * 2/ i_pos(8-39) - if ino has changed, but still in cache
630 * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
631 * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
632 *
633 * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
634 * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
635 * of i_logstart is used to store the directory entry offset.
636 */
637
1305edad
CH		 638static struct dentry *fat_fh_to_dentry(struct super_block *sb,
639 struct fid *fid, int fh_len, int fh_type)
1da177e4
LT		 640{
641 struct inode *inode = NULL;
642 struct dentry *result;
1305edad
CH		 643 u32 *fh = fid->raw;
644
645 if (fh_len < 5 || fh_type != 3)
646 return NULL;
1da177e4 647
17f95a7b
DH		 648 inode = ilookup(sb, fh[0]);
649 if (!inode || inode->i_generation != fh[1]) {
1da177e4
LT		 650 if (inode)
651 iput(inode);
652 inode = NULL;
653 }
654 if (!inode) {
655 loff_t i_pos;
656 int i_logstart = fh[3] & 0x0fffffff;
657
658 i_pos = (loff_t)fh[2] << 8;
659 i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
660
661 /* try 2 - see if i_pos is in F-d-c
662 * require i_logstart to be the same
663 * Will fail if you truncate and then re-write
664 */
665
666 inode = fat_iget(sb, i_pos);
667 if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
668 iput(inode);
669 inode = NULL;
670 }
671 }
1da177e4 672
44003728
CH		 673 /*
674 * For now, do nothing if the inode is not found.
675 *
676 * What we could do is:
677 *
678 * - follow the file starting at fh[4], and record the ".." entry,
679 * and the name of the fh[2] entry.
680 * - then follow the ".." file finding the next step up.
681 *
682 * This way we build a path to the root of the tree. If this works, we
683 * lookup the path and so get this inode into the cache. Finally try
684 * the fat_iget lookup again. If that fails, then we are totally out
685 * of luck. But all that is for another day
1da177e4 686 */
44003728
CH		 687 result = d_obtain_alias(inode);
688 if (!IS_ERR(result))
689 result->d_op = sb->s_root->d_op;
1da177e4
LT		 690 return result;
691}
692
693static int
694fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
695{
696 int len = *lenp;
697 struct inode *inode = de->d_inode;
698 u32 ipos_h, ipos_m, ipos_l;
699
700 if (len < 5)
701 return 255; /* no room */
702
703 ipos_h = MSDOS_I(inode)->i_pos >> 8;
704 ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
705 ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
706 *lenp = 5;
707 fh[0] = inode->i_ino;
708 fh[1] = inode->i_generation;
709 fh[2] = ipos_h;
710 fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
711 spin_lock(&de->d_lock);
712 fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
713 spin_unlock(&de->d_lock);
714 return 3;
715}
716
717static struct dentry *fat_get_parent(struct dentry *child)
718{
8f593427 719 struct super_block *sb = child->d_sb;
1da177e4
LT		 720 struct buffer_head *bh;
721 struct msdos_dir_entry *de;
722 loff_t i_pos;
723 struct dentry *parent;
724 struct inode *inode;
725 int err;
726
8f593427 727 lock_super(sb);
1da177e4
LT		 728
729 err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos);
730 if (err) {
731 parent = ERR_PTR(err);
732 goto out;
733 }
8f593427 734 inode = fat_build_inode(sb, de, i_pos);
1da177e4 735 brelse(bh);
44003728
CH		 736
737 parent = d_obtain_alias(inode);
1da177e4 738out:
8f593427 739 unlock_super(sb);
1da177e4
LT		 740
741 return parent;
742}
743
39655164 744static const struct export_operations fat_export_ops = {
1da177e4 745 .encode_fh = fat_encode_fh,
1305edad 746 .fh_to_dentry = fat_fh_to_dentry,
1da177e4
LT		 747 .get_parent = fat_get_parent,
748};
749
750static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
751{
752 struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb);
753 struct fat_mount_options *opts = &sbi->options;
754 int isvfat = opts->isvfat;
755
756 if (opts->fs_uid != 0)
757 seq_printf(m, ",uid=%u", opts->fs_uid);
758 if (opts->fs_gid != 0)
759 seq_printf(m, ",gid=%u", opts->fs_gid);
760 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
761 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
1ae43f82
OH		 762 if (opts->allow_utime)
763 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
1da177e4
LT		 764 if (sbi->nls_disk)
765 seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
766 if (isvfat) {
767 if (sbi->nls_io)
768 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
769
770 switch (opts->shortname) {
771 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
772 seq_puts(m, ",shortname=win95");
773 break;
774 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
775 seq_puts(m, ",shortname=winnt");
776 break;
777 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
778 seq_puts(m, ",shortname=mixed");
779 break;
780 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
781 /* seq_puts(m, ",shortname=lower"); */
782 break;
783 default:
784 seq_puts(m, ",shortname=unknown");
785 break;
786 }
787 }
788 if (opts->name_check != 'n')
789 seq_printf(m, ",check=%c", opts->name_check);
28ec039c
OH		 790 if (opts->usefree)
791 seq_puts(m, ",usefree");
1da177e4
LT		 792 if (opts->quiet)
793 seq_puts(m, ",quiet");
794 if (opts->showexec)
795 seq_puts(m, ",showexec");
796 if (opts->sys_immutable)
797 seq_puts(m, ",sys_immutable");
798 if (!isvfat) {
799 if (opts->dotsOK)
800 seq_puts(m, ",dotsOK=yes");
801 if (opts->nocase)
802 seq_puts(m, ",nocase");
803 } else {
804 if (opts->utf8)
805 seq_puts(m, ",utf8");
806 if (opts->unicode_xlate)
807 seq_puts(m, ",uni_xlate");
808 if (!opts->numtail)
809 seq_puts(m, ",nonumtail");
810 }
c1fca3b6
MS		 811 if (sbi->options.flush)
812 seq_puts(m, ",flush");
b271e067
JP		 813 if (opts->tz_utc)
814 seq_puts(m, ",tz=UTC");
1da177e4
LT		 815
816 return 0;
817}
818
819enum {
820 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
1ae43f82
OH		 821 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
822 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
823 Opt_immutable, Opt_dots, Opt_nodots,
1da177e4
LT		 824 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
825 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
826 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
b271e067 827 Opt_obsolate, Opt_flush, Opt_tz_utc, Opt_err,
1da177e4
LT		 828};
829
a447c093 830static const match_table_t fat_tokens = {
1da177e4
LT		 831 {Opt_check_r, "check=relaxed"},
832 {Opt_check_s, "check=strict"},
833 {Opt_check_n, "check=normal"},
834 {Opt_check_r, "check=r"},
835 {Opt_check_s, "check=s"},
836 {Opt_check_n, "check=n"},
837 {Opt_uid, "uid=%u"},
838 {Opt_gid, "gid=%u"},
839 {Opt_umask, "umask=%o"},
840 {Opt_dmask, "dmask=%o"},
841 {Opt_fmask, "fmask=%o"},
1ae43f82 842 {Opt_allow_utime, "allow_utime=%o"},
1da177e4 843 {Opt_codepage, "codepage=%u"},
28ec039c 844 {Opt_usefree, "usefree"},
1da177e4
LT		 845 {Opt_nocase, "nocase"},
846 {Opt_quiet, "quiet"},
847 {Opt_showexec, "showexec"},
848 {Opt_debug, "debug"},
849 {Opt_immutable, "sys_immutable"},
850 {Opt_obsolate, "conv=binary"},
851 {Opt_obsolate, "conv=text"},
852 {Opt_obsolate, "conv=auto"},
853 {Opt_obsolate, "conv=b"},
854 {Opt_obsolate, "conv=t"},
855 {Opt_obsolate, "conv=a"},
856 {Opt_obsolate, "fat=%u"},
857 {Opt_obsolate, "blocksize=%u"},
858 {Opt_obsolate, "cvf_format=%20s"},
859 {Opt_obsolate, "cvf_options=%100s"},
860 {Opt_obsolate, "posix"},
ae78bf9c 861 {Opt_flush, "flush"},
b271e067 862 {Opt_tz_utc, "tz=UTC"},
ae78bf9c 863 {Opt_err, NULL},
1da177e4 864};
a447c093 865static const match_table_t msdos_tokens = {
1da177e4
LT		 866 {Opt_nodots, "nodots"},
867 {Opt_nodots, "dotsOK=no"},
868 {Opt_dots, "dots"},
869 {Opt_dots, "dotsOK=yes"},
870 {Opt_err, NULL}
871};
a447c093 872static const match_table_t vfat_tokens = {
1da177e4
LT		 873 {Opt_charset, "iocharset=%s"},
874 {Opt_shortname_lower, "shortname=lower"},
875 {Opt_shortname_win95, "shortname=win95"},
876 {Opt_shortname_winnt, "shortname=winnt"},
877 {Opt_shortname_mixed, "shortname=mixed"},
878 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
879 {Opt_utf8_no, "utf8=no"},
880 {Opt_utf8_no, "utf8=false"},
881 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
882 {Opt_utf8_yes, "utf8=yes"},
883 {Opt_utf8_yes, "utf8=true"},
884 {Opt_utf8_yes, "utf8"},
885 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
886 {Opt_uni_xl_no, "uni_xlate=no"},
887 {Opt_uni_xl_no, "uni_xlate=false"},
888 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
889 {Opt_uni_xl_yes, "uni_xlate=yes"},
890 {Opt_uni_xl_yes, "uni_xlate=true"},
891 {Opt_uni_xl_yes, "uni_xlate"},
892 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
893 {Opt_nonumtail_no, "nonumtail=no"},
894 {Opt_nonumtail_no, "nonumtail=false"},
895 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
896 {Opt_nonumtail_yes, "nonumtail=yes"},
897 {Opt_nonumtail_yes, "nonumtail=true"},
898 {Opt_nonumtail_yes, "nonumtail"},
899 {Opt_err, NULL}
900};
901
41a34a4f 902static int parse_options(char *options, int is_vfat, int silent, int *debug,
1da177e4
LT		 903 struct fat_mount_options *opts)
904{
905 char *p;
906 substring_t args[MAX_OPT_ARGS];
907 int option;
908 char *iocharset;
909
910 opts->isvfat = is_vfat;
911
912 opts->fs_uid = current->uid;
913 opts->fs_gid = current->gid;
914 opts->fs_fmask = opts->fs_dmask = current->fs->umask;
1ae43f82 915 opts->allow_utime = -1;
1da177e4
LT		 916 opts->codepage = fat_default_codepage;
917 opts->iocharset = fat_default_iocharset;
918 if (is_vfat)
919 opts->shortname = VFAT_SFN_DISPLAY_LOWER|VFAT_SFN_CREATE_WIN95;
920 else
921 opts->shortname = 0;
922 opts->name_check = 'n';
923 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
924 opts->utf8 = opts->unicode_xlate = 0;
925 opts->numtail = 1;
28ec039c 926 opts->usefree = opts->nocase = 0;
b271e067 927 opts->tz_utc = 0;
1da177e4
LT		 928 *debug = 0;
929
930 if (!options)
8d44d974 931 goto out;
1da177e4
LT		 932
933 while ((p = strsep(&options, ",")) != NULL) {
934 int token;
935 if (!*p)
936 continue;
937
938 token = match_token(p, fat_tokens, args);
939 if (token == Opt_err) {
940 if (is_vfat)
941 token = match_token(p, vfat_tokens, args);
942 else
943 token = match_token(p, msdos_tokens, args);
944 }
945 switch (token) {
946 case Opt_check_s:
947 opts->name_check = 's';
948 break;
949 case Opt_check_r:
950 opts->name_check = 'r';
951 break;
952 case Opt_check_n:
953 opts->name_check = 'n';
954 break;
28ec039c
OH		 955 case Opt_usefree:
956 opts->usefree = 1;
957 break;
1da177e4
LT		 958 case Opt_nocase:
959 if (!is_vfat)
960 opts->nocase = 1;
961 else {
962 /* for backward compatibility */
963 opts->shortname = VFAT_SFN_DISPLAY_WIN95
964 | VFAT_SFN_CREATE_WIN95;
965 }
966 break;
967 case Opt_quiet:
968 opts->quiet = 1;
969 break;
970 case Opt_showexec:
971 opts->showexec = 1;
972 break;
973 case Opt_debug:
974 *debug = 1;
975 break;
976 case Opt_immutable:
977 opts->sys_immutable = 1;
978 break;
979 case Opt_uid:
980 if (match_int(&args[0], &option))
981 return 0;
982 opts->fs_uid = option;
983 break;
984 case Opt_gid:
985 if (match_int(&args[0], &option))
986 return 0;
987 opts->fs_gid = option;
988 break;
989 case Opt_umask:
990 if (match_octal(&args[0], &option))
991 return 0;
992 opts->fs_fmask = opts->fs_dmask = option;
993 break;
994 case Opt_dmask:
995 if (match_octal(&args[0], &option))
996 return 0;
997 opts->fs_dmask = option;
998 break;
999 case Opt_fmask:
1000 if (match_octal(&args[0], &option))
1001 return 0;
1002 opts->fs_fmask = option;
1003 break;
1ae43f82
OH		 1004 case Opt_allow_utime:
1005 if (match_octal(&args[0], &option))
1006 return 0;
1007 opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1008 break;
1da177e4
LT		 1009 case Opt_codepage:
1010 if (match_int(&args[0], &option))
1011 return 0;
1012 opts->codepage = option;
1013 break;
ae78bf9c
CM		 1014 case Opt_flush:
1015 opts->flush = 1;
1016 break;
b271e067
JP		 1017 case Opt_tz_utc:
1018 opts->tz_utc = 1;
1019 break;
1da177e4
LT		 1020
1021 /* msdos specific */
1022 case Opt_dots:
1023 opts->dotsOK = 1;
1024 break;
1025 case Opt_nodots:
1026 opts->dotsOK = 0;
1027 break;
1028
1029 /* vfat specific */
1030 case Opt_charset:
1031 if (opts->iocharset != fat_default_iocharset)
1032 kfree(opts->iocharset);
1033 iocharset = match_strdup(&args[0]);
1034 if (!iocharset)
1035 return -ENOMEM;
1036 opts->iocharset = iocharset;
1037 break;
1038 case Opt_shortname_lower:
1039 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1040 | VFAT_SFN_CREATE_WIN95;
1041 break;
1042 case Opt_shortname_win95:
1043 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1044 | VFAT_SFN_CREATE_WIN95;
1045 break;
1046 case Opt_shortname_winnt:
1047 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1048 | VFAT_SFN_CREATE_WINNT;
1049 break;
1050 case Opt_shortname_mixed:
1051 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1052 | VFAT_SFN_CREATE_WIN95;
1053 break;
1054 case Opt_utf8_no: /* 0 or no or false */
1055 opts->utf8 = 0;
1056 break;
1057 case Opt_utf8_yes: /* empty or 1 or yes or true */
1058 opts->utf8 = 1;
1059 break;
1060 case Opt_uni_xl_no: /* 0 or no or false */
1061 opts->unicode_xlate = 0;
1062 break;
1063 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1064 opts->unicode_xlate = 1;
1065 break;
1066 case Opt_nonumtail_no: /* 0 or no or false */
1067 opts->numtail = 1; /* negated option */
1068 break;
1069 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1070 opts->numtail = 0; /* negated option */
1071 break;
1072
1073 /* obsolete mount options */
1074 case Opt_obsolate:
1075 printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
1076 "not supported now\n", p);
1077 break;
1078 /* unknown option */
1079 default:
41a34a4f
CH		 1080 if (!silent) {
1081 printk(KERN_ERR
1082 "FAT: Unrecognized mount option \"%s\" "
1083 "or missing value\n", p);
1084 }
1da177e4
LT		 1085 return -EINVAL;
1086 }
1087 }
8d44d974
OH		 1088
1089out:
4de151d8 1090 /* UTF-8 doesn't provide FAT semantics */
1da177e4
LT		 1091 if (!strcmp(opts->iocharset, "utf8")) {
1092 printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
8d44d974
OH		 1093 " for FAT filesystems, filesystem will be "
1094 "case sensitive!\n");
1da177e4
LT		 1095 }
1096
1ae43f82
OH		 1097 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1098 if (opts->allow_utime == (unsigned short)-1)
1099 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
1da177e4
LT		 1100 if (opts->unicode_xlate)
1101 opts->utf8 = 0;
1102
1103 return 0;
1104}
1105
1106static int fat_read_root(struct inode *inode)
1107{
1108 struct super_block *sb = inode->i_sb;
1109 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1110 int error;
1111
1112 MSDOS_I(inode)->i_pos = 0;
1113 inode->i_uid = sbi->options.fs_uid;
1114 inode->i_gid = sbi->options.fs_gid;
1115 inode->i_version++;
1116 inode->i_generation = 0;
1117 inode->i_mode = (S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
1118 inode->i_op = sbi->dir_ops;
1119 inode->i_fop = &fat_dir_operations;
1120 if (sbi->fat_bits == 32) {
1121 MSDOS_I(inode)->i_start = sbi->root_cluster;
1122 error = fat_calc_dir_size(inode);
1123 if (error < 0)
1124 return error;
1125 } else {
1126 MSDOS_I(inode)->i_start = 0;
1127 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1128 }
1da177e4
LT		 1129 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1130 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1131 MSDOS_I(inode)->i_logstart = 0;
1132 MSDOS_I(inode)->mmu_private = inode->i_size;
1133
1134 MSDOS_I(inode)->i_attrs = ATTR_NONE;
1135 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1136 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1137 inode->i_nlink = fat_subdirs(inode)+2;
1138
1139 return 0;
1140}
1141
1142/*
1143 * Read the super block of an MS-DOS FS.
1144 */
1145int fat_fill_super(struct super_block *sb, void *data, int silent,
754661f1 1146 const struct inode_operations *fs_dir_inode_ops, int isvfat)
1da177e4
LT		 1147{
1148 struct inode *root_inode = NULL;
1149 struct buffer_head *bh;
1150 struct fat_boot_sector *b;
1151 struct msdos_sb_info *sbi;
1152 u16 logical_sector_size;
1153 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1154 int debug;
1155 unsigned int media;
1156 long error;
1157 char buf[50];
1158
8f593427
LT		 1159 /*
1160 * GFP_KERNEL is ok here, because while we do hold the
1161 * supeblock lock, memory pressure can't call back into
1162 * the filesystem, since we're only just about to mount
1163 * it and have no inodes etc active!
1164 */
f8314dc6 1165 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1da177e4
LT		 1166 if (!sbi)
1167 return -ENOMEM;
1168 sb->s_fs_info = sbi;
1da177e4
LT		 1169
1170 sb->s_flags |= MS_NODIRATIME;
1171 sb->s_magic = MSDOS_SUPER_MAGIC;
1172 sb->s_op = &fat_sops;
1173 sb->s_export_op = &fat_export_ops;
1174 sbi->dir_ops = fs_dir_inode_ops;
1175
41a34a4f 1176 error = parse_options(data, isvfat, silent, &debug, &sbi->options);
1da177e4
LT		 1177 if (error)
1178 goto out_fail;
1179
1180 error = -EIO;
1181 sb_min_blocksize(sb, 512);
1182 bh = sb_bread(sb, 0);
1183 if (bh == NULL) {
1184 printk(KERN_ERR "FAT: unable to read boot sector\n");
1185 goto out_fail;
1186 }
1187
1188 b = (struct fat_boot_sector *) bh->b_data;
1189 if (!b->reserved) {
1190 if (!silent)
1191 printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
1192 brelse(bh);
1193 goto out_invalid;
1194 }
1195 if (!b->fats) {
1196 if (!silent)
1197 printk(KERN_ERR "FAT: bogus number of FAT structure\n");
1198 brelse(bh);
1199 goto out_invalid;
1200 }
1201
1202 /*
1203 * Earlier we checked here that b->secs_track and b->head are nonzero,
1204 * but it turns out valid FAT filesystems can have zero there.
1205 */
1206
1207 media = b->media;
73f20e58 1208 if (!fat_valid_media(media)) {
1da177e4
LT		 1209 if (!silent)
1210 printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
1211 media);
1212 brelse(bh);
1213 goto out_invalid;
1214 }
803f445f 1215 logical_sector_size = get_unaligned_le16(&b->sector_size);
e7d709c0 1216 if (!is_power_of_2(logical_sector_size)
1da177e4 1217 || (logical_sector_size < 512)
9f354858 1218 || (logical_sector_size > 4096)) {
1da177e4
LT		 1219 if (!silent)
1220 printk(KERN_ERR "FAT: bogus logical sector size %u\n",
1221 logical_sector_size);
1222 brelse(bh);
1223 goto out_invalid;
1224 }
1225 sbi->sec_per_clus = b->sec_per_clus;
e7d709c0 1226 if (!is_power_of_2(sbi->sec_per_clus)) {
1da177e4
LT		 1227 if (!silent)
1228 printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
1229 sbi->sec_per_clus);
1230 brelse(bh);
1231 goto out_invalid;
1232 }
1233
1234 if (logical_sector_size < sb->s_blocksize) {
1235 printk(KERN_ERR "FAT: logical sector size too small for device"
1236 " (logical sector size = %u)\n", logical_sector_size);
1237 brelse(bh);
1238 goto out_fail;
1239 }
1240 if (logical_sector_size > sb->s_blocksize) {
1241 brelse(bh);
1242
1243 if (!sb_set_blocksize(sb, logical_sector_size)) {
1244 printk(KERN_ERR "FAT: unable to set blocksize %u\n",
1245 logical_sector_size);
1246 goto out_fail;
1247 }
1248 bh = sb_bread(sb, 0);
1249 if (bh == NULL) {
1250 printk(KERN_ERR "FAT: unable to read boot sector"
1251 " (logical sector size = %lu)\n",
1252 sb->s_blocksize);
1253 goto out_fail;
1254 }
1255 b = (struct fat_boot_sector *) bh->b_data;
1256 }
1257
1258 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1259 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1260 sbi->fats = b->fats;
1261 sbi->fat_bits = 0; /* Don't know yet */
1262 sbi->fat_start = le16_to_cpu(b->reserved);
1263 sbi->fat_length = le16_to_cpu(b->fat_length);
1264 sbi->root_cluster = 0;
1265 sbi->free_clusters = -1; /* Don't know yet */
606e423e 1266 sbi->free_clus_valid = 0;
1da177e4
LT		 1267 sbi->prev_free = FAT_START_ENT;
1268
1269 if (!sbi->fat_length && b->fat32_length) {
1270 struct fat_boot_fsinfo *fsinfo;
1271 struct buffer_head *fsinfo_bh;
1272
1273 /* Must be FAT32 */
1274 sbi->fat_bits = 32;
1275 sbi->fat_length = le32_to_cpu(b->fat32_length);
1276 sbi->root_cluster = le32_to_cpu(b->root_cluster);
1277
1278 sb->s_maxbytes = 0xffffffff;
1279
1280 /* MC - if info_sector is 0, don't multiply by 0 */
1281 sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
1282 if (sbi->fsinfo_sector == 0)
1283 sbi->fsinfo_sector = 1;
1284
1285 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1286 if (fsinfo_bh == NULL) {
1287 printk(KERN_ERR "FAT: bread failed, FSINFO block"
1288 " (sector = %lu)\n", sbi->fsinfo_sector);
1289 brelse(bh);
1290 goto out_fail;
1291 }
1292
1293 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1294 if (!IS_FSINFO(fsinfo)) {
b4cf9c34
VN		 1295 printk(KERN_WARNING "FAT: Invalid FSINFO signature: "
1296 "0x%08x, 0x%08x (sector = %lu)\n",
1da177e4
LT		 1297 le32_to_cpu(fsinfo->signature1),
1298 le32_to_cpu(fsinfo->signature2),
1299 sbi->fsinfo_sector);
1300 } else {
28ec039c 1301 if (sbi->options.usefree)
606e423e
OH		 1302 sbi->free_clus_valid = 1;
1303 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1da177e4
LT		 1304 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1305 }
1306
1307 brelse(fsinfo_bh);
1308 }
1309
1310 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1311 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1312
1313 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
803f445f 1314 sbi->dir_entries = get_unaligned_le16(&b->dir_entries);
1da177e4
LT		 1315 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1316 if (!silent)
1317 printk(KERN_ERR "FAT: bogus directroy-entries per block"
1318 " (%u)\n", sbi->dir_entries);
1319 brelse(bh);
1320 goto out_invalid;
1321 }
1322
1323 rootdir_sectors = sbi->dir_entries
1324 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1325 sbi->data_start = sbi->dir_start + rootdir_sectors;
803f445f 1326 total_sectors = get_unaligned_le16(&b->sectors);
1da177e4
LT		 1327 if (total_sectors == 0)
1328 total_sectors = le32_to_cpu(b->total_sect);
1329
1330 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1331
1332 if (sbi->fat_bits != 32)
1333 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1334
1335 /* check that FAT table does not overflow */
1336 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1337 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1338 if (total_clusters > MAX_FAT(sb)) {
1339 if (!silent)
1340 printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
1341 total_clusters);
1342 brelse(bh);
1343 goto out_invalid;
1344 }
1345
1346 sbi->max_cluster = total_clusters + FAT_START_ENT;
1347 /* check the free_clusters, it's not necessarily correct */
1348 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1349 sbi->free_clusters = -1;
1350 /* check the prev_free, it's not necessarily correct */
1351 sbi->prev_free %= sbi->max_cluster;
1352 if (sbi->prev_free < FAT_START_ENT)
1353 sbi->prev_free = FAT_START_ENT;
1354
1355 brelse(bh);
1356
1357 /* set up enough so that it can read an inode */
1358 fat_hash_init(sb);
1359 fat_ent_access_init(sb);
1360
1361 /*
1362 * The low byte of FAT's first entry must have same value with
1363 * media-field. But in real world, too many devices is
1364 * writing wrong value. So, removed that validity check.
1365 *
1366 * if (FAT_FIRST_ENT(sb, media) != first)
1367 */
1368
1369 error = -EINVAL;
1370 sprintf(buf, "cp%d", sbi->options.codepage);
1371 sbi->nls_disk = load_nls(buf);
1372 if (!sbi->nls_disk) {
1373 printk(KERN_ERR "FAT: codepage %s not found\n", buf);
1374 goto out_fail;
1375 }
1376
1377 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1378 if (sbi->options.isvfat) {
1379 sbi->nls_io = load_nls(sbi->options.iocharset);
1380 if (!sbi->nls_io) {
1381 printk(KERN_ERR "FAT: IO charset %s not found\n",
1382 sbi->options.iocharset);
1383 goto out_fail;
1384 }
1385 }
1386
1387 error = -ENOMEM;
1388 root_inode = new_inode(sb);
1389 if (!root_inode)
1390 goto out_fail;
1391 root_inode->i_ino = MSDOS_ROOT_INO;
1392 root_inode->i_version = 1;
1393 error = fat_read_root(root_inode);
1394 if (error < 0)
1395 goto out_fail;
1396 error = -ENOMEM;
1397 insert_inode_hash(root_inode);
1398 sb->s_root = d_alloc_root(root_inode);
1399 if (!sb->s_root) {
1400 printk(KERN_ERR "FAT: get root inode failed\n");
1401 goto out_fail;
1402 }
1403
1404 return 0;
1405
1406out_invalid:
1407 error = -EINVAL;
1408 if (!silent)
1409 printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
1410 " on dev %s.\n", sb->s_id);
1411
1412out_fail:
1413 if (root_inode)
1414 iput(root_inode);
1415 if (sbi->nls_io)
1416 unload_nls(sbi->nls_io);
1417 if (sbi->nls_disk)
1418 unload_nls(sbi->nls_disk);
1419 if (sbi->options.iocharset != fat_default_iocharset)
1420 kfree(sbi->options.iocharset);
1421 sb->s_fs_info = NULL;
1422 kfree(sbi);
1423 return error;
1424}
1425
7c709d00 1426EXPORT_SYMBOL_GPL(fat_fill_super);
1da177e4 1427
ae78bf9c
CM		 1428/*
1429 * helper function for fat_flush_inodes. This writes both the inode
1430 * and the file data blocks, waiting for in flight data blocks before
1431 * the start of the call. It does not wait for any io started
1432 * during the call
1433 */
1434static int writeback_inode(struct inode *inode)
1435{
1436
1437 int ret;
1438 struct address_space *mapping = inode->i_mapping;
1439 struct writeback_control wbc = {
1440 .sync_mode = WB_SYNC_NONE,
1441 .nr_to_write = 0,
1442 };
1443 /* if we used WB_SYNC_ALL, sync_inode waits for the io for the
1444 * inode to finish. So WB_SYNC_NONE is sent down to sync_inode
1445 * and filemap_fdatawrite is used for the data blocks
1446 */
1447 ret = sync_inode(inode, &wbc);
1448 if (!ret)
1449 ret = filemap_fdatawrite(mapping);
1450 return ret;
1451}
1452
1453/*
1454 * write data and metadata corresponding to i1 and i2. The io is
1455 * started but we do not wait for any of it to finish.
1456 *
1457 * filemap_flush is used for the block device, so if there is a dirty
1458 * page for a block already in flight, we will not wait and start the
1459 * io over again
1460 */
1461int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1462{
1463 int ret = 0;
1464 if (!MSDOS_SB(sb)->options.flush)
1465 return 0;
1466 if (i1)
1467 ret = writeback_inode(i1);
1468 if (!ret && i2)
1469 ret = writeback_inode(i2);
97e860d3 1470 if (!ret) {
ae78bf9c
CM		 1471 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1472 ret = filemap_flush(mapping);
1473 }
1474 return ret;
1475}
1476EXPORT_SYMBOL_GPL(fat_flush_inodes);
1477
1da177e4
LT		 1478static int __init init_fat_fs(void)
1479{
532a39a3 1480 int err;
1da177e4 1481
532a39a3
PE		 1482 err = fat_cache_init();
1483 if (err)
1484 return err;
1485
1486 err = fat_init_inodecache();
1487 if (err)
1488 goto failed;
1489
1490 return 0;
1491
1492failed:
1493 fat_cache_destroy();
1494 return err;
1da177e4
LT		 1495}
1496
1497static void __exit exit_fat_fs(void)
1498{
1499 fat_cache_destroy();
1500 fat_destroy_inodecache();
1501}
1502
1503module_init(init_fat_fs)
1504module_exit(exit_fat_fs)
1505
1506MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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